APC RESISTANCE AS AN ADDITIONAL THROMBOTIC RISK FACTOR IN A PATIENT SUFFERING FROM POLYCYTHEMIA-VERA AND RECURRENT THROMBOSIS

Patients with polycythemia vera (PV) have a high risk of thrombosis. H owever, thrombosis is not sufficiently predictable with standard diagn ostic procedures, We report on a patient with PV and recurrent thrombo sis who nevertheless had a low platelet count while under therapy with hydroxyurea. As a result of duodenal ulcer and gastrointestinal bleed ing, treatment with phenprocoumon was stopped years ago, Recently, het erozygosity for the factor V gene defect was diagnosed and anticoagula tion therapy was reconsidered. In conclusion? the presence of resistan ce to activated protein C was an additional thrombotic risk factor tha t was important for our decision to change the treatment strategy in o ur patient.